If I wanted a cheap diesel (ie/ budget wouldn't stretch to a decent Ford TDCi or newer-style BMW diesel), it would have to be a Rover every time.

I wouldn't have believed it until the first time I drove one as a courtesy car, so expect everyone else to be sceptical too, but I'd choose a Rover 400/45 turbo diesel every time and pocket the change. Great car to drive for a cheap old diesel.